Eye tracking and gaze tracking techniques are used to determine the direction of a person's gaze (i.e., the direction the person is looking) based on captured images. In doing so, a wide array of image analysis techniques may be employed. For example, in some embodiments, video images may be analyzed to determine the orientation of a person's head and/or the relative position of the person's pupil. Other common gaze tracking methods rely on the measurement of reflections of a known infrared (IR) light source on the cornea of the person being tracked. Such techniques generally include a dedicated IR camera (e.g., IR projector and sensor), which may require a significant cost and/or footprint on a mobile computing device.